The Arctic Climate Impact Assessment was released yesterday. It will be discussed by the Arctic Council (the governments of Canada, Denmark, Finland, Iceland, Norway, the Russian Federation, Sweden, and the U.S., as well as six indigenous-peoples organizations) at a meeting in Iceland today.

The four-year study of the Arctic climate involved an international team of more than 300 scientists. They used a number of climate models and made a "moderate estimate" of future emissions of carbon dioxide and other greenhouse gases that are widely believed to be contributing to the recent warming trend of the Earth's climate.

The study concluded that in Alaska, western Canada, and eastern Russia, average temperatures have increased as much as 4 to 7 degrees Fahrenheit (3 to 4 degrees Celsius) in the past 50 years, nearly twice the global average. Temperatures are projected to rise 7 to 13 degrees Fahrenheit (4 to 7 degrees Celsius) over the next hundred years.

The rising temperatures are likely to cause the melting of at least half the Arctic sea ice by the end of the century. A significant portion of the Greenland ice sheetwhich contains enough water to raise the worldwide sea level by about 23 feet (about 7 meters)would also melt.

The consequences of such a massive meltdown of northern ice would be dramatic, according to the study.

 Low-lying coastal areas in Florida and Louisiana could be flooded by the sea. A 1.5 feet (50-centimeter) rise in sea level could cause the coastline to move 150 feet (45 meters) inland, resulting in substantial economic, social, and environmental impact in low-lying areas.

 The health and food security of some indigenous peoples would be threatened, challenging the survival of some cultures.

 Should the Arctic become ice-free in summer, it is likely that polar bears and some seal species would become extinct.

 The melting of so much ice, and the resulting addition of so much fresh water to the ocean, could impact the circulation of currents and affect regional climate.